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March 2016: Retrofitting Standing Seam Roofs with External Enhancement Elements: Clamps

The wind-uplift capacities of standing seam roof systems vary considerably depending on the components used. Similar systems in appearance can have very different uplift resistances. Two roofs can be exposed to the same wind load, but only one sustains considerable damage. In many cases the field of the roof is secured adequately, but the corner or perimeter is not. This is because the same fastening method and rate are used across the entire roof. The higher uplift forces at the corners or perimeter can overload the roof securement and damage the corner or perimeter area. Many roof systems fail when panels deform under wind loads and disengage from the clips used to secure the panels. Wind forces on loose panels can peel back large areas of the roof system.

The Solution

Installing external clamping devices at the panel seams is one way to enhance wind-uplift resistance of certain standing seam roof systems without compromising their thermal movement capabilities. The device may be a proprietary assemble supplied by the roof system manufacturer or a clamp originally intended to secure snow guard systems. You can install snow guard clamps with aluminum rods perpendicular to the roof panel joints. The rods limit panel deflection, further increasing the uplift resistance.

Materials

The materials used should be based on the roofing system in place and the type of clamp arrangement selected. Additional materials may be needed. For snow guard clamps, a screw gun will be needed to drive the set screws. For rod arrangements, a sufficient number of 0.38 in. diameter aluminum or stainless steel rods will be needed. For proprietary clamps, either a wrench to secure bolt type arrangements or a drill-and-pop rivet to secure riveted arrangements. Before beginning work, contact Risk Logic to answer any questions so we can help identify the deficient areas of the roof and determine the best way to fix areas where unusual condition exist.